[PATCH 0/2] printk.kmsg: Ratelimit it by default

From: Borislav Petkov
Date: Tue Jun 14 2016 - 06:12:39 EST


From: Borislav Petkov <bp@xxxxxxx>

Ok, so how about these two?

Rostedt is busy so I took Linus' old patch and Steven's last v2 and
split and extended them with the comments people had on the last thread:

https://lkml.kernel.org/r/20160425145606.598329f2@xxxxxxxxxxxxxxxxxx

I hope, at least.

So it is ratelimiting by default, with "on" and "off" cmdline options. I
called the option somewhat a bit shorter too: "printk.kmsg"

The current use cases of this and of which I'm aware are:

* debug the kernel and thus shut up all interfering input from
userspace, i.e. boot with "printk.kmsg=off"

* debug userspace (and by that I mean systemd) by booting with
"printk.kmsg=on" so that the ratelimiting is disabled and the kernel log
gets all the spew.

Thoughts?

Thanks.

Borislav Petkov (2):
ratelimit: Extend to print suppressed messages on release
printk: Add kernel parameter to control writes to /dev/kmsg

Documentation/kernel-parameters.txt | 6 ++++
include/linux/ratelimit.h | 36 +++++++++++++++++++----
kernel/printk/printk.c | 57 +++++++++++++++++++++++++++++++------
lib/ratelimit.c | 6 ++--
4 files changed, 90 insertions(+), 15 deletions(-)

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2.7.3